These two Corsair RAM sets... difference?

Legend · 24 Dec 2018 at 13:44

Between the below two RAM sets, can someone possibly advise the difference (if any) and in-particular the suitability for a Ryzen 2700X system? They are both very similar. It might make zero difference, but I wanted to be sure, particularly if anyone has actually used either and had any issues.

Corsair CMK32GX4M2D3000C16 Vengeance LPX (2x16 GB) 3000MHz
Timings: 16-20-20-38

Corsair CMK32GX4M2B3000C15 Vengeance LPX (2x16 GB) 3000MHz
Timings: 15-17-17-35

The C16 appears to be a much newer revision, available since earlier this year, but I don't know if that means anything. The C15 has been around since before Ryzen even existed.

I need very low profile RAM, so it's between these two. The motherboard being used is the Asus ROG Strix X470 i-Gaming.

eeii · 24 Dec 2018 at 16:55

The difference is the CAS latency timings. Lower is better. Ryzen when it first came out was very fussy on RAM and would only run Samsung B die at 3200MHZ. Now its fine. I would recommend going to the motherboards web site and checking the RAM against the list of approved types for the motherboard you are buying (QVL). I suspect both will be fine. I would buy the CAS15 as lower is better.

lee32uk · 25 Dec 2018 at 18:27

Whichever is the cheapest.

mahius · 2 Jan 2019 at 10:57

Probably a bit late but here's the memory QVL list (page 19 is the bit you want): https://dlcdnets.asus.com/pub/ASUS/...TRIX-X470-I-GAMING-SUMMIT-Memory-QVL_0705.pdf

According to this, the latter part with C15 is listed here, but the exact C16 part number is not listed. It could very well be that this QVL list was made before the C16 part you've listed was released, the closest one on the list is CMK16GX4M2C3000C16, which looks like a previous revision of that C16 part you listed.

I'd go with the suggestion of the C15 memory.